Physicochemical wastewater treatment

Often, industrial wastewater does not meet the required standards (regional environmental legislation) for discharge and certainly not for reuse. First of all, the toxic components are to be removed from the wastewater. A range of physicochemical water treatment techniques are at disposal to remove unwanted components out of the wastewater. Following substances can be removed out of the water by physicochemical water treatment techniques:
  • Heavy metals
  • Suspended matter and emulsifying organic particles
  • Hardly degradable, non-polar organic substances
  • Oils and fats
  • Organic and inorganic components (e.g. phosphorus, salts)
  • Toxic pollutants
Physicochemical water treatment techniques are used as primary treatment, final treatment or specific treatment for reuse as process water.

Which physicochemical techniques are used in water treatment?

The type of water treatment depends primarily on the size of the particles present in the wastewater. Solid particles that are visible to the naked eye can be removed in three, relatively easy ways. These particles are removed by:

  • filtration
  • flotation
  • sedimentation

Fine suspended particles (< 1 µm) are more difficult to remove. These particles can only be removed by means of physicalchemical water treatment techniques.

Working method

We always start from lab tests with the wastewater. This way, it’s easy to determine which techniques are the most suitable.

  • flocculation
  • coagulation
  • flotation
  • neutralization
  • electroflotation
  • membrane technology – membrane filtration
  • NH3 stripper-absorbers
  • sludge treatment

For the separation of suspended solids, oils, fats and undissolved particles. This technique can be used as pretreatment for further purification or as sole treatment of the water. A commonly used flotation technique is Dissolved Air Flotation (DAF), in which air is dissolved under pressure in the water to be treated. Very fine bubbles bind with the floc particles in the water. These floc particles rise to the water surface and form a floating layer. In the next step, this floating layer is scraped off and collected in a container. That sludge can then be further thickened and/or dewatered.

Above all, the big advantage of this type of installation is that it can be fully automated. In other words, DAF is a very low maintenance technique.


Wastewater is neutralized (pH +- 7) to make it:

  • suitable for further degradation in a biological wastewater treatment plant
  • to meet discharge standards

Neutralization techniques involve adding chemicals to the wastewater. Some examples of neutralization units can be found below. It is a fairly compact set of storage and reaction tanks with the necessary dosing and mixing equipment. In addition to neutralizations, the pH of wastewater can also be changed for other reasons. Such as better control of chemical reaction rates, breaking of emulsions, conditioning, stabilization of raw wastewater, etc.

Neutralization is a technique applied to a wide variety of wastewaters. These types of installations are quite simple. Moreover, they can be fully automated and are therefore low maintenance. Due to the simple construction, the investment cost can also be kept low.

Membrane technology
Water treatment membrane techniques  are used for:
  • deferrization
  • soft water
  • demineralization
  • water reuse
Removal of NH3 or ammonia out of the water with strippers (stripping towers) – absorbers.
filter press for sludge dewatering
Sludge treatment

In many cases, sludge remains as a residue at the end of physicochemical water treatment processes. Usually, this  sludge residue is collected by third parties. Therefore, it is of economic importance to keep the volume of sludge as low as possible. One method of dewatering the sludge is the chamber filter press. Optionally, the presses can be equipped with a high-pressure spray system to clean the filter press cloths.

Physicochemical wastewater treatment plants – integrated solutions

Whether it is a completely new installation, or retrofitting or optimization of an existing installation, we offer you a correct solution, with an optimal price-quality ratio. Our installations are always seamlessly integrated into the existing situation of each production site. We aim for durable, maintenance-friendly and correctly dimensioned installations. In addition, we provide thorough training of the on-site maintenance staff to ensure that the wastewater treatment plant will continue to run smoothly in the long run. If despite this fact problems occur, we are always ready for a quick intervention.

Our expertise

Several companies from a wide range of industries (food, feed, recycling, automotive, pharma, chemical, …) already made or are making use of our expertise for the construction of water treatment installations. For all the above-mentioned specializations, we can present one or more references.